What makes it so great?Free yoga classes, 48 hours of paid time to volunteer, a $100 monthly wellness benefit, iPhone reimbursement, and a quarterly companywide forum hosted by founder Marc Benioff help explain the enthusiasm at this cloud computing pioneer.

After surveying over 277,000 employees of the participating companies, salesforce.com was ranked #19 - moving up 8 spots from last year.

Other companies on the list include Whole Foods, Zappos.com, American Express, Federal Express, Rackspace, Genentech, and Teach for America. Check out the Fortune's full list after the jump.